Exam 3 Spinal cord SG (pt1) Flashcards
Name the meninges of the spinal cord in sequence from outermost to innermost
Dura mater (outermost)
Arachnoid mater
Pia mater (innermost)
What is the relationship between spinal meninges and cranial meninges?
spinal meninges surround the spinal cord, and are continuous with the cranial meninges, which encircle the brain
Of what is the dura mater composed?
dense, irregular connective tissue
Name the substance within the: subdural space, subarachnoid space, central canal.
subdural space - interstitial fluid
subarachnoid space - CSF
central canal - CSF
What is the function of denticulate ligaments?
suspend the spinal cord within its dural sheath, protecting it against sudden displacement
What is the extent of the spinal cord in adults?
In adults the spinal cord extends from the medulla oblongata to the superior border of the second lumbar vertebra
Where in the vertebral column is the terminus of the conus medularis?
in adults ends at the level of the IV disc between vertebrae L1 & L2
Between which vertebrae is a spinal tap normally performed in adults?
between vertebrae L3 and L4, or between L4 and L5
Name the two roots of spinal nerves.
- Posterior (or dorsal) root
- Anterior (or ventral) root
What does the posterior root have with regard to sensory and/or motor function?
contains only sensory axons which conduct nerve impulses from sense receptors into the CNS
What does the anterior root have with regard to sensory and/or motor function?
Contains axons of motor neurons that conduct nerve impulses from the CNS to effector organs and cells
What is the causative agent of polio?
poliovirus
What nervous tissue does polio affect?
destroying cell bodies of motor neurons in the anterior horn of the spinal cord and in nuclei of cranial nerves
Describe ascending tracts regarding: direction of impulses carried, whether motor or sensory, white matter or gray matter.
comprise of axons that conduct nerve impulses toward the brain
Sensory
White matter tracts
Describe descending tracts regarding: direction of impulses carried, whether motor or sensory, white matter or gray matter.
carry nerve impulses down the spinal cord
Motor
White matter tracts
Describe the general functions of white matter and gray matter in the spinal cord.
White matter tracts ascend to or descend from the brain
Gray matter processes information input and output
How are spinal nerves named and numbered?
According to the region and level of the vertebral column from which they emerge
What is the general relationship between the exit of a spinal nerve from the vertebral column and a given vertebra?
Most spinal nerves exit inferior to the vertebra of the same number, except for cervical nerves
Why are there 8 pairs of cervical nerves, but only 7 cervical vertebrae?
Because C1 exits superior to the atlas (which is the first cervical vertebra)
Why do some spinal nerves
because spinal cord elongation stops about age 4 or 5 years, but vertebral column growth continues.
What spinal nerve roots comprise the cauda equina?
lower lumbar, sacral, and coccygeal nerves
What do posterior rami of spinal nerves supply?
deep muscles and skin of the dorsal surface of the trunk
What do anterior rami of spinal nerves supply?
muscles and structures of the upper and lower limbs and the skin of the lateral and ventral surfaces of the trunk
What spinal nerve component supplies the vertebrae and associated structures?
The meningeal branch of each spinal nerve
Which rami of spinal nerves form plexuses?
the anterior rami of spinal nerves
